Blade sharpening mechanism

ABSTRACT

A mechanism for sharpening blades such as razor blades comprises two sharpening stones mounted on a flexible frame which is subjected to a reciprocating or vibratory movement by a motor driven cam. A rotatable shaft related to the stones provides for clamping a blade to it so that when the shaft is turned in one direction one side of the blade edge bears against one of the reciprocating stones and when turned in the other direction the other side of the cutting edge bears against the other reciprocating stone, thereby sharpening the edge.

United States Patent 1 1 1111 3,875,702

Yacos Apr. 8, 1975 l l BLADE SHARPENING MECHANISM Primarv E.vaminer-Harold D. Whitehead G Y P k C tt 74 W. [76] Invgntor zgg z z cg g j i Attorney, Agent, or F1rmD. Gordon Angus; Donald Calif. 91024 [22] Filed: Jan. 11, 1973 57 ABSTRACT [21] Appl. No.: 322,908 A mechanism for sharpening blades such as razor blades comprises two sharpening stones mounted on a [52] U S Cl 51/58, 51/6} 51/159 flexible frame which is subjected to a reciprocating or [5 I] 3/48 vibratory movement by a motor driven cam. A rotatable shaft related to the stones provides for p g [58] Field of Search 51/58 59 159 a blade to it so that when the shaft is turned in one di- [56] References Cited rection one side of the blade edge bears against one of the reciprocating stones and when turned in the other UNITED STATES PATENTS direction the other side of the cutting edge bears 700,562 hRAuhl 5 against the other reciprocating tone thereby harpen- 991,86 ann..... in the ed 3.099.253 7/1963 Taylor 51/58 x g g 3,748,790 7/1973 Pizzaullo 51/58 3 Clalms, 4 Drawlng Figures BLADE 'SHARPENING MECHANISM This invention relates to mechanism for sharpening blades of the type provided with cutting edges such as razor blades. for example.

It is well-known to sharpen razor blades and other blades by holding the blade so that its opposite sides at the cutting edge are brought into contact with a sharpening element such as an abrasive or honing device. for example a honing wheel or carborundum stone or razor strop or the like, and producing relative motion be tween the blade and the sharpening surface. It has also been known to sharpen such blades by hand operated or motor driven sharpening wheels.

Such prior known mechanisms and arrangements have involved inconvenience or labor or manual operation or manual holding of the blade with variable sharpening results depending in large part on the technique or skill of the operator.

In accordance with the present invention the disadvantage of prior known sharpening mechanisms and methods are avoided by provision of a mechanism which is independent of technique or skill or labor of an operator. The invention is carried out by use of a sharpening stone arrangement supported on a frame sufficiently movable to be subject to reciprocation or vibration in a direction of reciprocation. Means is provided for reciprocating the frame in that direction to at least some degree of reciprocation or vibration. There is provided a supporting means for supporting the blade to be sharpened in such a position that the cutting edge of the blade can be caused to bear against the reciprocating or vibrating surface of the stone. The term stone as used herein means a sharpening element having a sharpening surface such as a carborundum stone or a strop or other sharpening surface.

According to a preferred feature the means for supporting the blade comprises a blade holder which can be reciprocated angularly back and forth so that in one position one side of the cutting edge is in contact with a stone and when in another position the other side of the cutting edge is in contact with a stone.

According to another preferred feature the frame supporting the stone or stones is provided with a flexibility sufficient to permit the reciprocating or vibratory motion of the frame.

According to another preferred feature the frame is reciprocated or vibrated by use of a power means such as an electric motor having a camming device or the like which imparts the reciprocating movement to the frame.

In using such a mechanism it is ordinarily not necessary for the operator to apply manual pressure of the blade against the stone, as the weight of the blade itself resting on the stone is generally sufficient to produce the sharpening result.

The foregoing and other features of the invention will be better understood from the following detailed description and the accompanying drawing of which:

FIG. 1 is an isometric view of a sharpening mechanism of which the interior is largely concealed by its cover, according to this invention;

FIG. 2 is a cross-section view taken at line 2-2 of FIG. 1;

FIG. 3 is a cross-section view taken at line 3-3 of FIG. 2; and

FIG. 4 is a cross-section view taken at line 44 of FIG. 2.

Referring to the drawing the mechanism is mounted on a base provided with a cover 11, best shown in FIG. 1, comprising four sides two of which, 12 and 13, appear in FIG. 1. The housing and cover together comprise a housing for the mechanism. The base 10 is rectangular and its longer side is herein considered to be the longitudinal dimension, and its shorter side is considered to be the transverse dimension. The cover has a top 14 provided with an opening 15 through which a blade 16 to be sharpened is inserted and attached. The top also has another opening 17 through which a finger operated knob 18 protrudes for orienting the blade during a sharpening operation. The sharpening is performed by use of two honing stones 19 and 20, for ex ample a carborundum type, spaced apart from each other and with their upper faces in the same horizontal plane. The stones are supported in this position by a frame comprising two similar U-members 21 and 22 spaced apart from each other. Each U-member comprises a pair of upstanding legs 23 and 24 joined at the bottom by a horizontal section 25 fitted into a depression 27 extending transversely in the base 10 and held firmly to the base by lips 26 protruding from the base. The upper ends of legs 23 and 24 are bent over at 27 and 28 to form outwardly extending horizontal flanges to which are attached respective flanges 29 and 30 of v a horizontal floor 31 which supports stones 19 and 20.

To maintain the stones in their proper positions the floor 31 is abruptly offset downwardly from flanges 29 and 30 so that the vertical offsets 61 thus formed, engage the outer edges of the respective stones 19 and 20. To hold the inner edges of the stones the floor 31 is provided with upstanding lips 32.

The frame members 21 and 22 are made of a flexible material such as a flexible or resilient steel or similar material so that although the base sections 25 are firmly secured to the base 10 there is enough flexure at the legs 23 and 24 so that the floor 31 can be moved or vibrated back and forth by an amount permitted by the flexibility of the material, in the direction shown by arrow 33 in FIGS. 3 and 4.

For the purpose of reciprocating the frame as indicated by these arrows there is provided an electric motor 34 fastened to a support 39 mounted on pedestals 40 and 41 secured to the base 10. The motor shaft 35 protrudes upwardly and has fastened to it a cam 36 having a camming pin 37 in a position offset from the axis of rotation of shaft 35. The pin 37 protrudes upwardly into a slot 38 best seen in FIG. 2. The slot extends longitudinally for a length sufficient to accommodate the cam pin 37 in all positions of the cam, but has a width only sufficient to accommodate the diameter of the pin so that rotation of the cam under power of the motor serves to move the floor 31 transversely as shown by arrow 33 but will not move the floor longitudinally as the cam pin exerts no pressure in the longitudinal direction against any wall of the slot. Due to the flexibility of the frame'members 21 and 22 the floor 31 is movable to the extent required by movement of pin 37.

For holding the blade to be sharpened there is provided blade holder in the form of a horizontal shaft 42 extending longitudinally and centrally at a position above the floor 31 and directly over slot 38 when in the unflexed position of frame members 21 and 22. The shaft 42 is rotatably mounted within bushings 43 and 44 near the opposite ends of the shaft, supported on respective upstanding pedestals 45 and 46 mounted on the base. The arrangement is such that the center of the shaft 42 is somewhat above the upper surfaces of stones l9 and 20.

At an intermediate portion of shaft 42 the shaft, which is cylindrical at both ends passing through the bushings, is formed to a cross-section of slightly less than a half cylinder, thereby providing a flat surface on which the backing member 48 of a typical blade to be sharpened may be fitted. Thus the length of flat portion 47 should be sufficient to accommodate the backing of any blade to be sharpened. At the ends of flat portion 47 the shaft rises upwardly at 49 and 50 by a distance equal to the thickness of the blade backing 48. At one end of the flat portion there is formed an indentation 51 in the shaft into which there is fitted a cover plate 52 which lies over the blade backing and is secured by a screw 53 which passes through a hole in the cover plate 52 and into a tapped hole part way through the shaft beyond the end of the flat portion 47 at the opposite end of the flat portion from indentation 51. At the end of the shaft related to opening 17 the finger wheel 18 is attached to the shaft. By manipulating this finger wheel in either direction as shown by arrows 54 the shaft can be turned so that the blade 16 hears against stone 19 as illustrated in FIGS. 1 and 3 or alternatively against the other stone 20.

The operation of the mechanism should now be apparent from the description of the drawing. The blade 16 to be sharpened is attached to the shaft 42 as shown and described. The electric plug 55 is plugged into an ordinary source of electric power and since it is connected through toggle switch 56 to the motor 34, operation of the toggle switch rotates the motor shaft in the direction of arrow 57 which vibrates the stones 19 and back and forth in the direction of arrows 33 as described. The finger wheel 18 is manipulated to move one side of the edge of the blade against one of the stones for example stone 19 as illustrated and kept in that position for a time while the stone moves in its reciprocating motion beneath the blade, which will sharpen the one side. Then the finger wheel 18 is manipulated to turn the shaft and hence the cutting edge of the blade as indicated by arrows 58, to the other stone which .brings the other side of the cutting edge into contact with the other stone 20 thereby sharpening that side.

It will be understood that the embodiment of the invention illustrated and described herein is given by way of illustration and not of limitation, and that modifications within the scope of the invention may suggest themselves to those skilled in the art.

I claim:

1. Mechanism adapted for sharpening handleless blades comprising: a flexible frame subject to reciprocation in a direction of reciprocating movement, a shaft capable of being rotated in both directions, a sharpening stone at each side of the shaft, means supporting the blade on the shaft with its cutting edge in a sharpening position on one or the other of the stones and means for reciprocating the frame in said direction so that the stones reciprocate and can bear against the cutting edge to sharpen it, whereby rotation of the shaft in one direction brings one side of the cutting edge in contact with one of the stones, and rotation of the shaft in the other direction brings the other side of the cutting edge in contact with the other of the stones, said mechanism including a base, said frame and said means supporting the blade being fixed to said base, said frame having vertically positioned flexible legs providing the said flexibility, and the stones having upper horizontal surfaces against which the cutting edge may bear, said stones being spaced apart from each other and said shaft extending horizontally at the space so that the blade is held at a position at the shaft slightly above the level of said stone surfaces.

2. Mechanism according to claim 1 including a motor beneath the stones, said motor having a vertical shaft whose axis is aligned with said space between the stones and a cam is attached to the shaft to engage the flexible frame to reciprocate it.

3. Mechanism according to claim 2 wherein the mechanism is substantially enclosed by a housing with an upper covering surface provided with an opening through it which leaves the blade holding means uncovered so that blades may be attached. 

1. Mechanism adapted for sharpening handleless blades comprising: a flexible frame subject to reciprocation in a direction of reciprocating movement, a shaft capable of being rotated in both directions, a sharpening stone at each side of the shaft, means supporting the blade on the shaft with its cutting edge in a sharpening position on one or the other of the stones and means for reciprocating the frame in said direction so that the stones reciprocate and can bear against the cutting edge to sharpen it, whereby rotation of the shaft in one direction brings one side of the cutting edge in contact with one of the stones, and rotation of the shaft in the other direction brings the other side of the cutting edge in contact with the other of the stones, said mechanism including a base, said frame and said means supporting the blade being fixed to said base, said frame having vertically positioned flexible legs providing the said flexibility, and the stones having upper horizontal surfaces against which the cutting edge may bear, said stones being spaced apart from each other and said shaft extending horizontally at the space so that the blade is held at a position at the shaft slightly above the level of said stone surfaces.
 2. Mechanism according to claim 1 including a motor beneath the stones, said motor having a vertical shaft whose axis is aligned with said space between the stones and a cam is attached to the shaft to engage the flexible frame to reciprocate it.
 3. Mechanism according to claim 2 wherein the mechanism is substantially enclosed by a housing with an upper covering surface provided with an opening through it which leaves the blade holding means uncovered so that blades may be attached. 